Step outside near any Delaware pond on a warm spring evening, and the racket of calling frogs can drown out conversation. That chorus comes from a surprising amount of diversity packed into a small state. According to a survey published on SnakeTracks, as of February 2023 there were twenty-two species of toads and frogs in the US state of Delaware, including nineteen frog species and four species of toads.
Learning the types of frogs in Delaware does not require a biology degree, just an eye for markings and an ear for calls. This guide covers six species that homeowners, hikers, and pond-watchers across the state are most likely to encounter, from a common backyard toad to the loudest frog in North America. Whether you are trying to pin down which native frogs in Delaware just started singing outside your window or you simply want a starting point for frog identification in Delaware, the details below cover size, color, habitat, and call for each species.
Important Note: Species counts vary slightly between sources depending on whether toads are counted separately from frogs and whether subspecies are listed individually. This guide focuses on six of the most frequently reported and easily observed species statewide.
| Species | Typical Size | Where to Find It | Best ID Clue |
|---|---|---|---|
| Eastern American Toad | 2–3.5 inches | Yards, gardens, woodland edges | Long musical trill |
| Pickerel Frog | 1.75–3 inches | Beaver ponds, cool streams | Two rows of square spots |
| Gray Treefrog | 1.25–2 inches | Trees near woodland ponds | Orange under hind legs |
| Southern Leopard Frog | 2–5 inches | Statewide wetlands and ponds | Rounded spots, pointed snout |
| Northern Cricket Frog | 0.6–1.4 inches | Pond and stream edges | Clicking, pebble-like call |
| Bullfrog | 3.6–6 inches | Permanent ponds, lakes, canals | Deep bellowing call |
1. Eastern American Toad
The Eastern American toad is a subspecies of the American toad, and according to Animal Spot, it is the most common toad in the Upper Delaware region. Its scientific name, Anaxyrus americanus americanus, reflects its status as one of the most widespread toads in the eastern United States, and it is a familiar sight in gardens, under porch lights, and along woodland trails throughout the state.
This species is mostly active after dark. Per The Frog Lady, the American toad is mainly nocturnal and most active in warm, humid weather, and during winter it burrows deep into the ground below the frost line, going deeper as the frost line drops. Outside of breeding season, this toad is highly terrestrial and only enters water for a short period while breeding and laying eggs, which is a key difference from the more water-dependent species covered later in this guide.
Listen for its call in early spring. It can be found in the northern Piedmont region of Delaware, and its call is a high musical trill that can last upwards of 30 seconds. That sustained trill is one of the easiest ways to separate this toad from the shorter, harsher calls of true frogs.
- Warty, dry skin in shades of brown, olive, or gray
- Prominent parotoid glands behind each eye
- Long, uninterrupted trilling call lasting up to 30 seconds
- Active mainly at dusk and after dark during warm, humid nights
The toad’s close relative, the Fowler’s toad, shares similar habits but tends to favor Delaware’s coastal plain rather than the Piedmont. For a broader look at how toad and frog diversity shifts region by region, the frog species found just across the border in Maryland make a useful comparison, since many Delmarva Peninsula species overlap between the two states.
2. Pickerel Frog
The pickerel frog, Lithobates palustris, is one of the easier true frogs to identify once you know what to look for. According to The Gardening Dad, it has two dark brown polka-dot-like rows on its back and paired vocal sacs. Compared to the similarly patterned Northern leopard frog, The Frog Lady notes that the pickerel frog has two parallel rows of squarish spots down its back rather than irregular round blotches.
This species has a built-in defense mechanism worth knowing about before handling one. The secretions it uses for defense on its skin are poisonous, though they are not dangerous to humans, and The Frog Lady adds that the toxic skin secretion makes the pickerel frog unappealing to most predators. Readers curious about how this compares to genuinely dangerous species can explore different types of poisonous frogs found elsewhere in the world for context.
Pro Tip: Because pickerel frog skin toxins can irritate other amphibians, avoid keeping one in the same container as other frog species, and always wash your hands after handling any wild frog.
Pickerel frogs favor quiet, vegetated water. They are often found near beaver ponds with dense vegetation, and their call reflects their preference for calm water. According to New Jersey’s Department of Environmental Protection, whose regional frog guide describes the same species found throughout the Delmarva area, the pickerel frog’s voice sounds like a snore, low-pitched and with a short duration. Breeding typically runs from March into May, right around the time the next species on this list starts calling from the treetops.
3. Gray Treefrog
Delaware is actually home to two nearly identical gray treefrogs: the Eastern gray treefrog, Hyla versicolor, and Cope’s gray treefrog, Hyla chrysoscelis. Per Gone Froggin, the two Gray Tree Frogs are nearly identical besides their calls and chromosome numbers, meaning most people in the field will never tell them apart by sight alone.
Both species share the treefrog family’s signature camouflage trick. According to Bird Watching HQ, this incredible frog can slowly change colors to match what it is sitting on, varying from gray to green or brown, and it is common for their back to display a mottled coloring, much like lichen. Gray treefrogs are ubiquitous throughout Delaware, showing up in a wide variety of wooded habitats from backyards to forests to swamps.
| Feature | Eastern Gray Treefrog | Cope’s Gray Treefrog |
|---|---|---|
| Skin texture | Slightly rougher, more mottled | Smaller and smoother-skinned |
| Call | Slower, more musical trill | Faster, harsher trill |
| Best ID method | Call and chromosome count | Call and chromosome count |
Both frogs stay hidden most of the year. They stick to the treetops until it is time to breed, and their breeding call is a repeated, abrupt, nasal bark that is typically the best way to locate them. They also time reproduction carefully: gray treefrogs prefer to mate and lay eggs in woodland ponds without fish, which protects their eggs and tadpoles from being eaten.
Anyone comparing tree frogs Delaware to those found in cooler New England climates might find it useful to browse the tree frog and chorus frog species documented in Connecticut, many of which share close relatives with Delaware’s populations.
4. Southern Leopard Frog
The Southern leopard frog, Lithobates sphenocephalus, ranks among the most widely distributed true frogs in the state. Per Gone Froggin, it is a medium to large sized frog that is brown or green in color with spots over its body, and it can be found statewide. Its slim build and pointed snout help separate it from the stockier, rounder pickerel frog described earlier.
Its voice is distinctive once you know what to listen for. The Frog Lady describes the southern leopard frog’s call as sounding like a squeaky balloon or a chuckling croak, a sound that carries easily across open wetlands on warm nights.
Breeding is prolific: females may deposit 3,000 to 5,000 eggs in a cluster within the water, giving this species one of the largest single clutches among Delaware’s native frogs.
- Brown or green background color with rounded, dark spots
- Slender body with a pointed snout, unlike the blunter pickerel frog
- Call resembles a squeaky balloon or a chuckling laugh
- Found statewide in ponds, ditches, and slow-moving wetlands
Because leopard frogs and pickerel frogs are often confused at a glance, comparing spot shape and body proportion side by side is the fastest way to tell them apart in the field. Readers building a broader mental catalog of spotted frog species may also want to check the population found in North Carolina, where several leopard frog relatives share overlapping range with Delaware’s population.
5. Northern Cricket Frog
Small enough to overlook, the Northern cricket frog, Acris crepitans, is a member of the treefrog family that spends almost no time in trees. According to SnakeTracks, this frog belongs to the tree frog family and can be found across the US, Canada, and Mexico, though it does not actually live in trees. Instead, it sticks close to the water’s edge, and the same source notes it can be found along ponds, streams, lakes, and rivers throughout Delaware.
Physical identification comes down to a few small details. These frogs have very warty skin, webbed toes, and a triangle mark between their eyes, and their hind limbs are fairly long without the sticky toe pads typical of climbing tree frogs. Coloring varies from individual to individual: they are usually gray, light brown, or green with a mid-dorsal stripe that is typically orange or brown, along with dark bands on their thighs and a line running from each eye to the forelimb.
Pro Tip: Cricket frogs are diurnal, unlike most Delaware frogs. The best time to spot one is during the day near open, sunny banks rather than at night with a flashlight.
This species is diurnal, and its call sounds like two stones being quickly clicked together, a sound many people mistake for insect noise rather than a frog. Some regional guides list this species as the “Eastern cricket frog,” and according to The Frog Lady, it is one of Delaware’s smallest frogs at an average of one inch in length, with females slightly larger, and it can jump a surprisingly long way of five to six feet for its size.
That leaping ability, paired with its habit of hunting small insects along muddy banks, means it often turns up in the same habitats favored by the state’s common fly species found near Delaware wetlands, which make up part of its diet.
6. Bullfrog
No list of Delaware frogs is complete without the American bullfrog, Lithobates catesbeianus, the giant of the group. According to Bird Watching HQ, adult body lengths range from 3.6 to 6 inches, coloration is typically olive green with gray or brown mottling or spots, the back feet are fully webbed, and individuals can grow to weigh as much as 1.5 pounds. That places the bullfrog well above every other species in this guide in both length and weight.
Size is not the only thing that sets it apart. Gone Froggin notes that the American bullfrog is the largest frog in the state and is found near permanent bodies of water such as large ponds, streams, and lakes. It closely resembles the green frog, but it lacks the dorsal ridge running down the back that green frogs have, and instead its ridge wraps around the tympanum, or eardrum.
Key Insight: Confirmed as Delaware’s largest frog species, the bullfrog also has an outsized appetite, which sets it apart ecologically from every other species on this list.
That appetite is part of what makes the bullfrog notable to wildlife watchers. Per Delawonder, this is Delaware’s largest frog species and a common sight around many bodies of water, including ponds, swamps, creeks, and canals, and bullfrogs are ambitious predators, with rodents and birds even found in their stomachs.
Breeding behavior is equally assertive: during the breeding season, male frogs select egg sites in shallow water that they defend aggressively, a female will then select a male by entering his territory, and the species is named for its deep call, thought to sound like a bull bellowing.
- Largest frog in Delaware, reaching up to 6 inches and 1.5 pounds
- No dorsal ridge down the back, unlike the similar green frog
- Deep, resonant call resembling a bellowing bull
- Opportunistic predator that eats insects, small rodents, and birds
Because bullfrogs share territory and prey with many of Delaware’s reptiles, they often turn up in the same habitat notes as the state’s native snake species that hunt along the same pond edges. Conservation officials also track amphibians alongside reptiles for a reason: according to Delaware’s Department of Natural Resources and Environmental Control, amphibian species in the Northeast face threats including wetland loss, water pollution, and habitat fragmentation, with vernal pool-breeding amphibians representing an especially vulnerable group.
Together, these six species show just how much variety hides in Delaware’s ponds, forests, and backyards. From the long trill of the Eastern American toad to the bull-like bellow that gives the bullfrog its name, each species offers its own clues for identification, whether that means checking spot shape, listening for a distinctive call, or simply noting where along the water’s edge a frog was found.
For anyone wanting to keep exploring, the broader question of how many frog species exist worldwide or a look at the wider diversity of frog types found across the country makes a fitting next stop, as does a look at the insect life these frogs depend on, including the beetle species that make up part of the local food web and the wasps found in the same Delaware habitats.